In order to save costs and make network deployment more conveniently, operators hope that a long term evolution (LTE) could use a same site as an existing universal mobile telecommunication system (UMTS), and in order to guarantee the communication quality of a cell edge user, it is required that the LTE could achieve a same coverage as the UMTS system. The LTE divides different channels over a physical layer to carry different information, it is required to evaluate a coverage of each channel of the LTE, identify a coverage-limited channel, and finally consider a method capable of enhancing the coverage of the channel.
It is possible to evaluate the coverage of each channel of the LTE according to a maximum coupling loss (MCL) value, the smaller the MCL value, it indicates that the smaller the coverage of a corresponding channel. A physical uplink shared channel (PUSCH) is used to transmit uplink data services, when the PUSCH is used for data service transmission at a medium rate (hereinafter referred to as a PUSCH medium data rate), its MCL value is the smallest compared with MCL values of other channels, the coverage is the worst, and its coverage is required to be improved. Where, the PUSCH medium data rate refers to a rate between 128 kbps and 384 kbps generally.
In order to improve the coverage, a transmission time interval (TTI) bundling (TTI bundling) method can be used, the TTI bundling in the prior art can only be applied in a scenario of a quadrature phase shift keying (QPSK) modulation with the number of resource blocks (RB) being less than or equal to 3. In this scenario, the maximum value of a transport block size (TBS) is 504 bits. Then, even if initial transmission is 100% correct at this time, when four sub-frames are bundled, the maximum data rate is only 5044 ms=126 kbps, whereas the PUSCH medium data rate is in the range of 128 kbps to 384 kbps generally, the rate requirement for the PUSCH medium data rate cannot be achieved after using the TTI bundling. That is to say, the existing TTI bundling scheme cannot be applied in the scenario of the PUSCH medium data rate directly, a solution to improve the coverage at the PUSCH medium data rate requires to be considered.